Cork

How to make cork fabric?

Cork fabric to make handbags.

Bag Affair is, as other brands are, using cork as main material for the handbags and accessories. Cork which is worked as a tissue, is flexible and light, vegan and natural and capable to replace leather. 

But do you actually know how this material is made? If not, you will find here the ultimate guide to know how cork textile is made.

Please note that we can only advice on the way it is done in Portugal and especially in our factories. We cannot give any guaranty where other brands get their materials from and how they work.

Cork leather – a misleading term 

But first of all a short introduction why we are writing “cork textile or cork fabric” and not “cork leather”. We explain this in some other blogs as well, but leather in the definition of the word and usage is a product from animal. Leather is never vegan. Leather is made from animal skin, which is treated and tanned to be transformed for shoes, bags, clothes or furniture upholstery. This for cork leather is misleading as a term. And what we will explain later on, there are brands mixing leather and cork for one material. This means that “cork leather” exists, but indeed is not vegan. Bag Affair is PETA vegan approved and all cork we use is backed with cotton and fully vegan. This for: cork textile or cork fabric. 

Starting with a cork tree

To make any cork product you first of all need cork. Cork grows all around the Mediterranean and if you want to learn more you can read our blog article about the cork forest, where to find cork and the diverse ecological system. The biggest country of cork is Portugal, producing over 70% of worldwide quantity. Further Bag Affair works with Portugal as this is where you find all forests tightly controlled by the government and all forests FSC certified. 

Cork harvest – an art on its own 

Cork trees need time to grow and after plantation you need to wait 25 years for the first harvest. At this point of harvest the bark is still young and breaks easy. This quality cannot be use for wine stoppers or textile but it will be fully used for example for pin boards or isolation. Following this first cork harvest every 9 years a tree can be harvested. 

The harvest is controlled and all workers harvesting the bark are employed from Portuguese government to assure when and where they will harvest, under which conditions, etc. Harvest season is between middle of May and July each year – temperature needs to be warm enough and humidity lower than in spring without it being too dry. In older times the calculation has been based on the moon circles but as now you can better measure meteorically indications, this is not applied strictly anymore. 

cork is harvested on the trunk only

The cork is harvested on the trunk only and never on the branches which will still grow further. At the point the branches start on the trunk of the tree, harvest will be stopped. Harvesting is hard work but relatively well paid. As it is very seasonal the workers are working the rest of the year on different jobs and can get some financial help from the government. The harvest is done with axe. The person cutting the bark put the hand close to the axe to feel how deep they can cut. This needs a lot of training but is very important as if a tree is cut, the tree will never produce new cork on the cut section. Further if the cut is too deep, the tree might catch some illness and could in worst case die. 

Once the bark cut it is collected to be transported from the fields to the factory, on the tree a number is marked. As cork harvest is done every 9 years, only the last digit of a year is market with white, non-toxic paint. For example the photos we show and our video are from 2019. The number on the tree is a 9. The next harvest will be in 2028 for these trees, so no need to write “19” or “2019” – a minimum of paint is best for the tree. 

Cork treatment – water only please

While growing, cork trees are never watered and never any pesticides or fertilizers are used and when it comes to treating the cork after harvest, the strategy is the same. Less is best. 

The cork barks are collected and stacked on pallets of 600 to 700 kilo. 

These pallets are boiled in water in huge tanks. This process will use the water several times and not consume big quantities, but this step is important to assure that all fungus and bacteria which are in the barks get killed. Remember that the trees are never in contact with any pesticide which means that fungus and bacteria could grow uncontrolled. These will eventually lead to “corked wine” or irregular look and structure in the colour. This needs to be avoided. 

The boiling process further will help that the cork will flatten just by the heat and the weight of the cork staked. There is not something like machines flattening the cork. 

And this is actually it:

no further or different treatment, no chemicals, nothing very special. The water in which the cork has been boiled has nothing added to it and is normal waste without any risk of pollution.

The cork needs to rest and dry between three to four months. Once the cork dried the pieces are tested and quality controlled. They are cut in regular shapes of around 45 to 25 cm. 

Following these pieces can be used for the cork textile as well as for bottle closures, be transformed into yoga blocks or any other items you might know from cork. 

Cork fabric – slice and glue

For the cork textile the middle section, which is the most dense and best quality one, is used. The cork pieces are sliced in three layers and only the middle one is treated further. The inner and outer layers are used for other products. 

The middle layer itself is following sliced again in layer of 0,3 to 0,4 mm if to obtain a “traditional” look of the textile. Or they are first coloured and cut into pieces for example, following glued to one block and then sliced again. To glue cork at this state can be done only by applying heat. No glue is needed as the natural glue from the trees, called “resin” is strong enough. 

These thin slices need a backing as without they will easily break. And here it comes to the tricky point! This backing can be basically anything. As mentioned before it could be leather. But it can be as well polyester or polyamide or again cotton which is mixed or layered with polyutherane (PU). All these options are not natural as either treated before (leather) or plastics. Whenever you mix a natural, recyclable and biodegradable material with another one which has not the same qualities, the final result cannot keep up to the promise.

Means if you mix natural cork with Polyester for example you will obtain a textile but which is plastic based, not biodegradable or recyclable. In our opinion this makes no sense. To first grow cork over so many years, assure quality no chemicals, etc. to following mix with plastics. 

This is why we work only cotton based. 

This is a huge point of difference compared to other brands and we really cannot tell you how the other cork bags are made. Please contact each brand and investigate. Polyester and PU are used as it makes the textile smoother and easier to work and cheaper than how we work. So this is a tricky point and not all brands will be transparent about it. 

We work based with cotton which is bought in rolls an on which a natural and water-based glue is applied by hand. Following the thin cork slices are applied by hand as well. Either one next to each other, either in a way to get a different structure, here are not limits. What is important is to assure that the textile is fully covered with cork. We work with a technique in which the cork is placed over layering at the edges of each piece.

Following the textile is pressed and grinded. To obtain a smooth result without using chemicals or PU this is done by hand in three steps. As the edges have been overlaid this will result in dust which again is used and not waste. 

After this very manual work you obtain perfect and best quality cork fabric- and this is how it is done! 

Cork fabric is a zero waste product

As mentioned before all parts of the cork bark are used. The first harvest is used for isolation. The middle layer for textile or for wine closures and the inner and outer layer are used for granulates. These are needed for champagne closures or isolation or again yoga blocks or pin walls. Even the dust, which appears when cutting the cork or at the step of sanding of the textile, is not waste. The dust is burned and produces energy for the used machinery. This can be up to 70% of the energy used depending on product and production facility. 

If you want to learn more about cork and the Bag Affair products, check out the other blog articles, visit the beautiful country of Portugal or contact us! 

watch how it’s made here:

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